Heat transfer liner and tube shield



Feb. 28, 1961 J. c. MCADAM HEAT TRANSFER LINER AND TUBE SHIELD Filed Aug. 1, 1958 IN V EN TOR.

HHI

ATTOEA/FKS.

HEAT TRANSFER LINER AND TUBE SHIELD John C. McAdam, Burbank, Calif., assignor to International. Electronic Research Corporation, Burbank, Calif., a corporation of California Filed Aug, 1, 1958, Ser. No. 752,457

3*Claims. Cl. 174-35 The invention relates to tube shields for use with electronic components and electronic tubes wherein the tube shield is so constructed that it is capable of picking up heat from the surface of the component or tube and transferring it through a surrounding tube shield envelope to the base primarily by conduction, at which point heat is dissipated to the mounting.

The invention further comprehends a heat dissipating tube shield which is also constructed in such fashion that the effects of vibration in the mount which might be detrimental to the performance or long life of the component are substantially minimized.

In relatively recent years the industry has learned of the marked advantages in carrying away from electronic components and tubes heat which is often generated in substantial quantities when the tubes are performing in their normal fashion. As the conditions have changed to circumstances wherein more and more tubes are compacted within a limited space, the heat dissipating problem has correspondingly increased. Also for the same reason .where many tubes and components are compacted within a small space on vehicles, for example, which suffer an exceptional amount of high frequency vibration, the .mortality in electronic tubes has increased appreciably and to the extent that positive means for minimizing the effect of vibration as well as heating has become highly desirable.

Some tube shield devices have been developed to satisfy the requirements mentioned and performancewise these devices have been acceptable and effective. Due to the fact, however, that the tube shield liners are subjected to repeated heating and cooling cycles, some problems have arisen with respect to the form and character of the, resilient. tube shield liner in order that it continue its effective performanceover long periods of time without the necessity of frequent servicing. Many of the tube shield liners heretofore employed have either been unnecessarily. costly for a great variety of installations where dependability has been a primary requisite or have limited effectiveness where they have been constructed inexpensively and in a single piece due to certain limitations in the mode of manufacture.

It is therefore among the objects of the invention to provide anew and improved heat transfer liner and tube shield combination wherein the elements are particularly simple and non-complicated with respect to manufacturing requirements and technique and which at the same time incorporate many of the advantages heretofore available only in the more intricate heat dissipat- 'ing tube shields and liners.

Another object of the invention is to provide a new and improved heat transfer liner for electronic tube shields which can be constructed of a single strip of resilient material in such fashion that a very high degree of resilient contact is provided on the inside capable of engaging a substantial portion of the tube or component and'wherein a lesser portion on the outer side is made ;use of. for. engagement with the surrounding sleeve, there- 2,973,400 Patented Feb. 28,1961

by making most effective use of the available area of the liner.

Still another object of the invention is to provide a new and improved heat transfer liner for electronic tube shields which can be constructed by forming a strip of selected material essentially fiat in an initial form such that after the strip is curved and fitted within a sleeve, the liner assumes a new and different form which is highly advantageous from the point of view of contact, heat dissipation and the inhibiting of-the transfer of vibrations.

Still further among the objects of the invention is to provide a new and improved heat transfer liner and tube shield combination wherein the parts cooperate with each other in such fashion that the respective engagements of the liner with the tube and the liner with the surrounding sleeve are proportioned in order to have the combination perform in the most effective manner.

With these and other objects in view, the invention consists of the construction, arrangement and combina tion of the various parts of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings. r

In the drawings:

Figure 1 is a side perspective view of the heat trans fer liner and tube shield combination shown mounted upon a base in position of engagement with an electronic tube.

Figure 2 is a plan view of the liner in the form had prior to insertion within the sleeve.

Figure 3 is a plan view of the liner and sleeve combination. 4. 1

Figure 4 is an end elevational view of a portion of the liner in the form had prior to insertion within the sleeve.

In an embodiment of the invention chosen for the purpose of illustration there is shown a base 10 adapted for attachment to some conventional chassis by means of holes 11. The base is so constructed that it is adapted to receive an electronic component in the form of an electronic tube indicated generally by the reference character 12, the tube being provided with a base portion 13.

Fitting slidably over the base is a metallic sleeve 14 which makes use of slits 15 having apertures 16 therein for reception of dimples 17 on the exterior of the base whereby to firmly but releasably anchor the sleeve to the base. At the upper end of the sleeve is an annular inwardly turned flange 18 defining a relatively large opening 19. i

A liner is indicated generally by the reference character 20 and is shown in position between the tube 12 and sleeve 14 in Figure l. The liner is shown separately in Figures 2 and 4 in the form existing prior to insertion of the liner Within the sleeve.

More particularly, the liner comprises a single sheet of metallic material which has a resilient character dependable under all conditions of use and which will maintain its resilient character with a high degree of efficiency when. subjected to frequent heating and cooling cycles over long periods of time. Beryllium copper has been found to have the desired characteristics and r'eferenceis made to this material by way of example.

When the liner is formed initially, there are provided a series of spaced parallel ribs 21 which in plan view have the form of elongated rectangles and whose outer surfaces 22 are substantially flat. In the chosen embodiment the ribs are uniformly and equally spaced one from another, the space between ribs being substantially greater than the breadth of the ribs. Between the ribs are intermediate portions 23 substantially wider than the ribs and entirely the s eesabs wesath r bs. 31 imm e portions have arcuate sides 24 which join longitudinal side edges of the ribs with the intermediate portions. The arcuate portions are gently arcuate at the point of junction or tangen-cywith the intermediateportion but joins the ribs at a relatively sharp angle. The ribs and intermediate portions may be formed in an acceptable manner either by rolling or die forming. It will also be appreciated that the strips can be of any convenient length longer than might be needed for any single tube shield liner and that the strip can be cut at will anywhere along its length.

As shownjin FigureB, cuts arem-ade adjacent the ribs through the arcuate. sides leaving short legs in order to have the ribs overlap each other, thereby to anchor the ends with respect to each other. Due to the springiness of the material it is not necessary that the ribs interlock precisely and hence the .endmost ribs can be retained precisely the same breadth as all of the other ribs.

After the liner has been formed in the manner described, it is turned upon itself as illustrated in Figure 3 and inserted within the sleeve 14. The number of sections employed should be such that the liner is not stretched unnecessarily when placed within the sleeve but rather should be such that if it is necessary to help the liner fit within the sleeve, it can be puckered slightly. Due to the inherent resiliency in the intermediate portions, they will assimilate a very substantial degree of adjustment.

When the combined liner and sleeve is to be employed in the manner shown in Figure 1, they are slid together over the outer end of the tube during which operation the intermediate portions 23 will yield substantially, thereby to accommodate the surface of the tube. The yielding is sufliciently variable so that even though the outside dimension ofthe' tube varies considerably throughout its length, the intermediate portions will form an etiective engagement Furthermore, by reason of the same inherent resilience throughout the entire area of the intermediate portions, the liner can be used repeatedly for different tubes under circumstances where the outside diameters of the tubes might vary considerably from one tube to another. The construction of the liner is such that it will readily accommodate itself to a great number of variations in size and contour without suffering any permanent deformation.

Under certain special circumstances as, for example, where a liner might need to be'made of material somewhat heavier in gage than on other occasions, added versatility may be built into the liner by providing slots 27. The-slots 27 have approximately the proportionate width shown and need have a length no greater than the breadth of the intermediate portions between the arcuate sides. An effective pattern is one illustrated in Figure 2 wherein the slots are parallel and uniformly spaced throughout the length of the intermediate portions and wherein they provide resilient patches which are more or less square.

When in use, whether with or without slots, the intermediate portions exert a resilient force which not only impresses those portions into contact with the surface of the component or tube, but also exerts a resilient pressure outwardly, thereby pressingthe surfaces of the ribs into firm heat conducting contact with the surrounding sleeve. The firmness of contact at all areas is instrumental in providing a path for conducting heat generated in the tube through the'line'r, the sleeve and the base to the chassis. It will be appreciated also that some heat is dissipated by radiation from the exterior of the sleeve. Moreover, the same resilient contact by which the intermediate portions uniformly engage all variations in the surface of the tube is also instrumental in minimizing the transfer of damaging vibrations from the chassis to the tube. A uniformly large area of contact is provided which is effective in spreading the desirable effect uniformly over substantially the entire exterior surface of the component so that there will be virtually no unevenness in the pick up of heat or in they absorption of vibrations.

While I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A heat dissipating and vibration resistant shielding liner for use in holding a circumferentially arcuate electronic component in a surrounding sleeve comprising a strip of homogeneous inherently resilient heat conducting metallic material, said strip comprising pairs of outwardly extending corners defining a series of spaced ribs each being of predetermined breadth between the corners and presenting areas adapted to engage the surrounding sleeve, said liner including intermediate portions of said metallic material between corners of adjacent ribs having a breadth greater than the breadth of the ribs, each said portion having side sections of arcuate form curving towards each other and joining a mid-section therebetween with a tangential junction, whereby when the liner and sleeve are applied to a component the intermediate portions throughout the span thereof between adjacent corners yield resiliently upon engagement with the component.

2. A heatdissipating and vibration resistant shielding liner for use in holding a circumferentially arcuate electronic component in a surrounding sleeve comprising a continuous strip of homogeneous inherently resilient heat conducting metallic material having opposite side edges, said strip comprising pairs of clearly defined outwardly extending corners defining a series of spaced ribs each being of fixed breadth between the corners and presenting outwardly facing areas adapted to engage the surrounding sleeve, said liner including intermediate portions of said metallic material between corners of adjacent ribs having a breadth greater than the breadth of the ribs, each said portion prior to insertion of the component having side sections of arcuate form curving towards each other and joining a mid-section therebetween with a tangential junction, each said mid-section subsequent to insertion of a component having an outwardly arcuate shape and tangential junctions with the adjacent arcuate sections, the span of said outwardly arcuate shape and the lengths of the arcuate sections being determined throughout the length of the component by the perimeter of. the component whereby, when the liner and a sleeve are applied to a component, the ribs at the side edges of the liner are interlocked at the outwardly facing areas and the area of engagement of the liner with the component exceeds the area of engagement of the liner with the sleeve.

3. A heat dissipating and vibration resistant shield for use in holding a circumferentially arcuate electronic component comprising a substantially cylindrical sleeve and a liner therein of homogeneous inherently resilient metallic material, said liner comprising pairs of clearly defined outwardly extending corners defining a series of spaced ribs each being of predetermined breadth between the corners and presenting outwardly facing areas adapted to engage the surrounding sleeve, said liner including inter mediate portions of said metallic material .between corners of adjacent ribs having a breadth greater than the breadth of the ribs, each said portion prior to application to the component having side sections of arcuate form curving towards each other and joining a mid-section therebetween with a tangential junction, each said midsection subsequent to insertion of a component having an outwardly arcuate shape and tan-gential junctions with the adjacent arcuate sections, the span of. said outwardly arcuate shape and the lengths of the arcuate s tions being determined throughout the length of the component by the perimeter of the component whereby when the shield is applied to the component the area of engagement of the liner with the component exceeds the area of engagement of the liner with the sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 6 Woods Sept. 24, 1957 Woods Sept. 22, 1959 OTHER REFERENCES Publication I, Heat Reducing Tube Shield," Collins Technical Bulletin 301 (4 pages), copy received US. Patent Oflice Mar. 23, 1956.

Publication II, Electron Tube Reliability, published in Electromechanical Design, January-February 1958 2,745,895 Lideen May 15, 1956 10 (pages 16 and 17 relied on). I 

